package 分类.二维动归;

public class 不同路径 {
    public int uniquePaths(int m, int n) {
       int[][] dp=new int[m][n];
       for (int i=0;i<m;i++){
           dp[i][0]=1;
       }
       for (int i=0;i<n;i++){
           dp[0][i]=1;
       }

       for (int i=1;i<m;i++){
           for (int j=1;j<n;j++){
               dp[i][j]=dp[i-1][j]+dp[i][j-1];
           }
       }

       return dp[m-1][n-1];
    }
    public int uniquePaths_01(int[][] obstacleGrid) {
        int m=obstacleGrid.length;
        int n=obstacleGrid[0].length;
        int[][] dp=new int[m][n];
        for (int i=0;i<m;i++){
            if(obstacleGrid[i][0]==1){
                dp[i][0]=0;
                break;
            }else {
                dp[i][0]=1;
            }

        }
        for (int i=0;i<n;i++){
            if(obstacleGrid[0][i]==1){
                dp[0][i]=0;
                break;
            }else {
                dp[0][i]=1;
            }
        }

        for (int i=1;i<m;i++){
            for (int j=1;j<n;j++){
                if(obstacleGrid[i][j]==1){
                    dp[i][j]=0;
                    continue;
                }else {
                    dp[i][j]=dp[i-1][j]+dp[i][j-1];
                }

            }
        }

        return dp[m-1][n-1];
    }
}
